Silsesquioxanes (SQs) with formulas that are [RSiO1.5]n where n=8, 10, 12, 14 or [RMe2SiOSiO1.5]8 are unique molecules. They can be considered to represent nanometer size silica particles with functionality substantially evenly spaced on their surfaces in all three dimensions. Furthermore, in some instances this functionality can be the same or mixed.
As such, they provide access to nanocomposite materials with control of assembly at nano meter length scales in 1-, 2- or 3-dimensions one nanometer at a time. The silica core provides the rigidity and heat capacity of larger silica particles making these compounds and coatings or thin films made from them quite robust. In principle, the ability to assemble “cubes” nm×nm offers the potential to tailor (e.g. tailor materials properties) at nanometer length scales. Tailoring at such length scales should permit full optimization of global properties on an application-by-application basis and at low cost. It will also aid in obtaining high reproducibility, predictability and therefore effective materials design. Information about the above can be gleaned from one or more of the following references, all of which are hereby incorporated by reference for all purposes:    1. C. Zhang, F. Babonneau, C. Bonhomme, R. M. Laine, C. L. Soles, H. A. Hristov, A. F. Yee, “Highly Porous Polyhedral Silsesquioxane Polymers. Synthesis and Characterization,” J. Am. Chem. Soc. 120, 8380-91 (1998).    2. R. M. Laine, C. Zhang, A. Sellinger, L. Viculis, “Polyfunctional Cubic Silsesquioxanes as Building Blocks for Organic/Inorganic Hybrids,” J. Appl. Organometallic Chem. 12, 715-23 (1998).    3. E. K. Lin, C. R. Snyder, F. I. Mopsik, W. E. Wallace, W. L. W. C. X. Zhang, R. M. Laine “Characterization of Epoxy-Functionalized Silsesquioxanes as Potential Underfill Encapsulants,” in Organic/Inorganic Hybrid Materials, MRS Symp. Ser. Vol. 519, R. M. Laine, C. Sanchez, C. J. Brinker, E. Giannelis eds. 1998 pp. 15-20.    4. M. C. Gravel, C. Zhang, M. Dinderman, R. M. Laine “Octa(3-chloroammonium-propyl)octasilsesquioxane,” J. Appl. Organomet. Chem. 13, 329-36 (1999).    5. R. M. Laine, M. Asuncion, S. Baliat, N. L. Dias Filho, J. Harcup, A. C. Sutorik, L. Viculis, A. F. Yee, C. Zhang, and Q. Zhu, “Organic/Inorganic Molecular Hybrid Materials From Cubic Silsesquioxanes,” in Organic/Inorganic Hybrid Materials, MRS Symp. Ser. Vol. 576, L. Klein, M. De Guire, F. Lorraine, J. Mark eds. December 1999 pp. 3-14.    6. C. Zhang, R. M. Laine “Hydrosilylation of allyl alcohol with [HSiMe2OSiO1.5]8. Octa (3-hydroxypropyldimethylsiloxy)octasilsesquioxane and its octamethacryl-ate derivative as potential precursors to hybrid nanocomposites,” J. Am. Chem. Soc. 122, 6979-88 (2000).    7. C. L. Soles, E. K. Lin, W-L. Wu, C. Zhang, and R. M. Laine, “Structural Evolution of Silsesquioxane-based Organic/Inorganic Nanocomposite Networks,” in Organic/Inorganic Hybrid Materials—2000, MRS Symp. Ser. Vol. 628, R. M. Laine, C. Sanchez, and C. J. Brinker, eds. Mater. Res. Soc., 2001, CC4.2.1-6.    8. R. M. Laine, J. Choi, I. Lee, “Organic-Inorganic Nanocomposites with Completely Defined Interfacial Interactions,” Adv. Mater. 13, 800-3 (2001).    9. R. O. R. Costa, W. L. Vasconcelos, R. Tamaki, and R. M. Laine, “Organic/Inorganic Nanocomposite Star Polymers via Atom Transfer Radical Polymerization of Methyl Methacrylate Using Octafunctional Silsesquioxane Cores,” Macromol., 34, 5398-407, (2001).    10. C. Zhang, T. J. Bunning, R. M. Laine, “Synthesis and Characterization of Liquid Crystal-line (LC) Silsesquioxanes,” Chem. of Mater.; 13; 3653-62 (2001).    11. J. Choi, J. Harcup, A. F. Yee, Q. Zhu, R. M. Laine, “Organic/inorganic hybrid composites from cubic silsesquioxanes,” J. Am. Chem. Soc. 123, 11420-30 (2001).    12. R. Tamaki, Y. Tanaka, M. Z. Asuncion, J. Choi, R. M. Laine, “Octa(aminophenyl)silsesquioxane as a Nanoconstruction Site,” J. Am. Chem. Soc. 123, 12416-7 (2001).    13. R. Tamaki, J. Choi, R. M. Laine “A Polyimide Nanocomposite from Octa(aminophenyl)silsesquioxane” Chem. Materials 15, 793-7 (2003)    14. J. Choi, R. Tamaki, S. G. Kim, R. M. Laine, “Organic/Inorganic Imide Nanocomposites from Aminophenylsilsesquioxanes,” Chem. Mater. 15 3365-3375 (2003).    15. Jiwon Choi, Albert F. Yee, and Richard M. Laine, “Organic/Inorganic Hybrid Composites from Cubic Silsesquioxanes. Epoxy Resins of Octa(dimethylsiloxyethylcyclohexylepoxide)Silsesquioxane,” Macromolecules 15, 5666-82 (2003).    16. J. Choi, A. F. Yee, R. M. Laine, “Toughening of cubic silsesquioxane epoxy nanocomposites using core shell rubber particles; a three component hybrid system,” Macromol. 37 3267-76 (2004).    17. C. M. Brick, Y. Ouchi, Y. Chujo, R. M. Laine, “Robust Polyaromatic Octasilsesquioxanes from Polybromophenylsilsesquioxanes, BrxOPS, via Suzuki Coupling,” Macromol. 38, 4661-5 (2005).    18. C. M. Brick, R. Tamaki, S-G. Kim, M. Asuncion, M. Roll, T. Nemoto, R. M. Laine, Spherical, Polyfunctional Molecules Using Polybromooctaphenylsilsesquioxanes as Nanoconstruction Sites,” Macromol. 38, 4655-60 (2005).    19. S. G. Kim, J. Choi, R. Tamaki, R. M. Laine, “Synthesis of amino-containing oligophenyl-silsesquoixanes, Polymer, 46, 4514-4524 (2005).    20. M. Z. Asuncion, I. Hasegawa, J. Kampf, R. M. Laine, “The selective dissolution of rice hull ash to form [OSiO1.5]8[R4N]8 (R=Me, CH2CH2OH) octasilicates. Basic nanobuilding blocks and possible models of intermediates formed during biosilification processes,” Materials Chemistry 15, 2114-21 (2005).    21. R. M. Laine, “Nano-building blocks based on the [OSiO1.5]8 silsesquioxanes,” J. Mater. Chem., 15, 3725-44 (2005).    22. A. Sellinger, R. Tamaki, R. M. Laine, K. Ueno, H. Tanabe, E. Williams, G. E. Jabbour, “Solution processable nanocomposites based on silsesquioxane cores for use in organic light emitting diodes (OLEDs),” Chem. Comm., 3700-02 (2005).    23. H. Cheng, R. Tamaki, R. M. Laine, F. Babonneau, Y. Chujo, and D. R. Treadwell, “Neutral Alkoxysilanes from Silica,” J. Am. Chem. Soc. 122, 10063-72 (2000).    24. “Well-defined nanosized building blocks for organic/inorganic nanocomposites,” R. M. Laine, R. Tamaki, J. Choi, WO 02/100867 A1 Dec. 19, 2002.    25. M. D. Stewart, J. T. Wetzel, G. M. Schmid, F. Palmieri, E. Thompson, E. K. Kim, D. Wang, K. Sotodoeh, K. Jen, S. C. Johnson, J. Hao, M. D. Dickey, Y. Nishimura, R. M. Laine, D. J. Resnick, C. G. Willson, Proc. SPIE-Int. Soc. Opt. Eng. 5751, 219 (2005).    26. I. Hasegawa, R. M. Laine, M. Asuncion, N. Takamura, “Facile Synthesis of the Cubeoctameric Silicate Anion, Si8O208-, its dimethylsilyl derivative, Si8O20[Si(CH3)2H]8 and certain derivatives therefrom,” U.S. Patent Application publication, 2005/0142054, Jun. 30, 2005.    27. S. Sulaiman, C. M. Brick, C. M. De Sana, J. M. Katzenstein, R. M. Laine, R. A. Basheer, “Tailoring the Global Properties of Nanocomposites. Epoxy Resins with Very Low Coefficients of Thermal Expansion,” Macromolecules 39 5167-9 (2006).    28. K. Takahashi, S. Sulaiman, J. M. Katzenstein, S. Snoblen, R. M. Laine, “New Aminophenylsilsesquioxanes, Synthesis, Properties and Epoxy Nanocomposites,” Australian J. Chem. 59, 564-70 (2006).    29. C. Brick, E. R. Chan, S. C. Glotzer, D. C. Martin, R. M. Laine, “Self-lubricating nano ball bearings,” Adv. Mater. 19, 80-2 (2007).    30. M. Z. Asuncion, R. M. Laine, “Silsesquioxane Barrier Materials,” Macromolecules, 40 555-62 (2007).    31. N. Takamura, L. Viculis, R. M. Laine “A completely discontinuous organic/inorganic hybrid nanocomposite based on reactions of [HMe2SiOSiO1.5]8 with vinylcyclohexene,” International Polymer 56, 1378-1391 (2007).    32. M. F. Roll, M. Z. Asuncion, J. Kampf, R. M. Laine, “para-Octaiodophenylsilses-quioxane, [p-IC6H4SiO1.5]8, a nearly perfect nanobuilding block,” ACS Nano 2, 320-26, (2008).    33. S.-G. Kim, S. Sulaiman, D. Fargier, R. M. Laine, “Simple syntheses of octaphenyloctasilsesquoxane and polyphenylsilsesquioxane. Starting point for aromatic nanocomposites with complete control of physical and chemical properties at nanometer length scales,” in Materials Syntheses. A Practical Guide. Eds. U. Schubert, N. Hüsing, R. Laine, Springer-Verlag, Wein 2008, pp. 179-182.    34. R. M. Laine, M. Roll, M. Asuncion, S. Sulaiman, V. Popova, D. Bartz, D. J. Krug, P. H. Mutin; “Perfect and Nearly Perfect Silsesquioxane (SQs) Nanoconstruction Sites and Janus SQs,” J. Sol-Gel Sci. Tech. 46, 335-347 (2008).    35. R. M. Laine, D. Bartz, D. J. Krug, V. Popova, M. Z. Asuncion “Bi- and trifunctional silsesquioxanes for novel coating applications,” filed June, 2007. PTO filed August 2008.    36. S. Sulaiman, A. Bhaskar, J. Zhang, R. Guda, T. Goodson III, R. M. Laine, “Molecules with perfect cubic symmetry as nanobuilding blocks for 3-D assemblies. Elaboration of octavinylsilsesquioxane. Unusual luminescence shifts may indicate extended conjugation involving the silsesquioxane core.” Chem Mater. 20 5563-5573 (2008).    37. M. Z. Asuncion, M. F. Roll, Richard M. Laine, “Octaalkynylsilsesquioxanes, Sea Urchin Molecular connectors for 3-D-Nanostructures,” Macromolecules, 41 8047-8052 (2008).
See also, commonly owned co-pending Published U.S. Application Publication No. 20090012317 (Laine et al, published on Jan. 9, 2009), PCT Application Publication No. WO 2009/002660 (filed on Jun. 2, 2008), and PCT Application No. PCT/US2009/052965 (filed on Aug. 6, 2009) all hereby incorporated by reference for all purposes.
The use of silane coating systems to modify the surface characteristics of a material has been the source of attention in the art, with efforts directed at monosilanes and disilanes. For these latter types of silane coating systems, the resulting species typically bonds only once or twice to the surface as illustrated in the following Reaction (1). The one and two bonds to the surface can be easily hydrolyzed off during washing with water or simple detergents or even physically removed by mild abrasion and thus the surface protection or modification is lost.
The use of functional disilanes as suggested by reaction (2) may provide better and harder coatings but the intermediates are sometimes hard to prepare and also, they can dimerize without forming coatings, as discussed by Loy et al. [D. A. Loy, K. J. Shea, “Bridged Polysilsesquioxanes. Highly Porous Hybrid Organic-Inorganic Materials, Chem. Rev., 95, 1431-42 (1995), incorporated by reference herein.

The literature on hard coatings for protective purposes is quite extensive. There are fields of study on coatings for corrosion resistance, scratch and abrasion resistance, decorative purposes, light absorbing, light transmitting, as low-k dielectric materials, as low friction surfaces, biocidal surfaces, hydrophobic, etc. It is usually recognized that not every coating can satisfy the needs of every application. Further, there is often a trade-off of properties. A coating suitable for one purpose may exhibit some other characteristic making it unsuitable for another purpose. For example, hard coatings that are designed to be scratch resistant are also likely to be brittle. Coatings that are transparent are typically not designed to selectively absorb UV light. Alternately coatings that are transparent are often not transparent to UV light. Coatings that are adherent to metals are not necessarily also adherent to plastic or glass or ceramic or wood. Coatings that are hydrophobic are not necessarily also hard or resistant to deformation or abrasion. It would be attractive to be able to achieve improved balancing of properties to render coatings more useful in multiple applications.
Accordingly, there remains a need in the art for additional materials that can be used as coatings, and particularly hard coatings, in a substrate and that exhibit the ability to form multiple Si—O bonds to surfaces that are strong and difficult to break, and that exhibit an attractive balance of properties.